165 (number)

165 (one hundred [and] sixty-five) is the natural number following 164 and preceding 166.

In mathematics
165 is:
 * an odd number, a composite number, and a deficient number.
 * a sphenic number.
 * a tetrahedral number
 * the sum of the sums of the divisors of the first 14 positive integers.
 * a self number in base 10.
 * a palindromic number in binary (101001012) and bases 14 (BB14), 32 (5532) and 54 (3354).
 * a unique period in base 2.

In astronomy

 * 165 Loreley is a large Main belt asteroid
 * 165P/LINEAR is a periodic comet in the Solar System
 * The planet Neptune takes about 165 years to orbit the Sun.

In the military

 * Caproni Ca.165 Italian fighter aircraft developed before World War II
 * USNS American Explorer (T-AOT-165) was a United States Navy tanker, part of the U.S. Reserve Fleet, Beaumont, Texas
 * USS Bonita (SS-165) was a United States Navy Barracuda-class submarine during World War II
 * USS Bullock (AK-165) was a United States Navy Alamosa-class cargo ship during World War II
 * USS Counsel (AM-165) was a United States Navy Admirable-class minesweeper during World War II
 * USS Counsel (AM-165) was a United States Navy Haskell-class attack transport during World War II
 * USS Flicker (IX-165) was a United States Navy minesweeper during World War II
 * USS Georgetown (AG-165) was a United States Navy Oxford-class technical research ship following World War II
 * USS Meredith (DD-165) was a United States Navy Wickes-class destroyer during World War I
 * USS Parks (DE-165) was a United States Navy Cannon-class destroyer escort during World War II
 * USS Prince Georges (AP-165) was a United States Navy Crater-class cargo ship transport and cargo ship during World War II
 * USS Wenonah (SP-165) was a United States Navy yacht during World War I
 * The 165 Squadron, Republic of Singapore Air Force Air Defence Operations Command, Republic of Singapore Air Force

In transportation

 * British Rail Class 165
 * The Blériot 165 was a French four-engine biplane airliner of the early 1920s
 * The Cessna 165 single-engine plane of the 1930s
 * LOT Polish Airlines Flight 165, en route from Warsaw to Cracow Balice airport crashed during a snowstorm on April 2, 1969

In other fields
165 is also:
 * The year AD 165 or 165 BC
 * 165 AH is a year in the Islamic calendar that corresponds to 781 – 782 CE
 * The atomic number of an element temporarily called Unhexpentium
 * G.165 is a Telecommunication Standardization Sector standard for echo cancellers, used in telephony
 * The human gene Zinc finger protein 165, or ZNF165